2016-08-18
Adrian Price
Blending water with electricity
In the days when steam trains served farmers and rural communities with a wide variety of goods, dams were built to provide water for the steam trains at frequent intervals. One such dam is at Amery, near Dowerin and had a corrugated iron roof built over the dam to minimise evaporation which in that area is about 1.7 metres annually, a major loss of water.
A new initiative is to cover dams with floating solar panels to provide power to pump water, desalinate water and also power homes and towns. These solar panels would also minimise evaporation. Some people are concerned that too much land may be allocated to solar farms; solar panels on dams serve several purposes.
Inland salinity
Most of the WA Wheatbelt is more than 300 metres above sea level but salinity is a growing problem of former food producing land. For many years I sampled water in bores, dams, creeks for salinity and pH. In most areas the saline water table was rising as much as 500mm annually, causing expansion of salt lakes and killing crops and bushland.
It is generally considered that this rising water table is a result of land clearing over the last century or so and is still impacting despite the trend for reduced rainfall during the last 30 years. An impact on many towns is the rising salt degrading mortar and brickwork of buildings. Most Wheatbelt towns are now affected.
Some attempts to address salinity include 'deep drainage. These drains have been dug with sheer sides to a depth of 2-4 metres. If an animal falls in, there is no way out. There may be several of these drains in a paddock; fighting a bushfire in such areas could result in fire fighters being unable to escape a fast moving fire. The water being drained is usually highly saline and acidic and is certainly unsuitable to be drained into waterways, which has been the case.
The soils in the WA Wheatbelt are capable of producing a wider variety of vegetables, fruit and nuts if suitable water was available. Climatically, most of our Wheatbelt is not as harsh as the region around Griffith NSW, a major fruit and vegetable growing area, but here there is water of sufficient quality for irrigation.
Water pollution
Many rural rubbish tips have contributed to pollution of waterways; the latest guidelines are designed to minimise this contamination but the old rubbish tips continue to ooze pollution long after closure.
Overuse of chemical fertilisers and herbicides/pesticides are other contaminants.
Anyone who has picked up litter along rural roadsides will be aware that they have prevented this litter from entering roadside drains and then on to rivers and the ocean.
Activities such as fracking which are proposed for many agricultural areas of WA place our finite underground drinking and irrigation water supplies at risk.
Good water is highly valued, especially as our populations increase and at the same time as rainfall decreases. Water, our greatest liquid asset.
Too much good drinking water is flushed down the toilet.
Photos: Header – A typical Wheatbelt dam Adrian Price; Floating solar panels, Japan Ciel&Terre